• On October 12, the club declined to renew the contracts for bench coachJerry Narron and bullpen coachCraig Bjornson.^[19]
• On October 12, MLB announced that the Red Sox would have the fourth pick in the2021 MLB draft, their highest pick since the1967 MLB draft.^[20]
• On October 23, pitcherDomingo Tapia was claimed off of waivers by theSeattle Mariners.^[21]
• On October 26, the team outrighted five players toTriple-A, removing them from the 40-man roster:Zack Godley,Mike Kickham,Robinson Leyer,Tzu-Wei Lin, andAndrew Triggs.^[22] Godley, Kickham, and Triggs declined their assignments, electing to becomefree agents.^[22]
• On October 28, three more players were outrighted to Triple-A:Dylan Covey,José Peraza, andCésar Puello; Peraza and Puello elected free agency.^[23]
• On October 28,Jackie Bradley Jr. andCollin McHugh elected free agency.^[24]

• On November 1, the team declined to exercise their $6.85 million option forMartín Pérez for the 2021 season, paying him a $500,000 buyout and making him a free agent.^[25]
• On November 6,Alex Cora was re-hired as the team's manager.^[26]
• On November 16, the team signed pitcherKevin McCarthy to a minor-league contract.^[27]
• On November 17, the team signed outfielderMichael Gettys to a minor-league contract.^[27]
• On November 20, the deadline to protect players in advance of theRule 5 draft scheduled for December, the team made multiple roster moves:^[28]
  • Three players were removed from the 40-man roster:Matt Hall andRyan Weber weredesignated for assignment, and the team outrightedKyle Hart to Triple-A.
  • Seven players were added to the 40-man roster, thus protecting them from being selected in the Rule 5 draft:Eduard Bazardo,Jay Groome,Bryan Mata,Hudson Potts,Jeisson Rosario,Connor Seabold, andConnor Wong.
• On November 20, changes to Cora's uniformed coaching staff were announced:^[29]Will Venable was added to the staff as bench coach andJason Varitek was added as game planning coordinator;Kevin Walker, who had been assistant pitching coach, was named bullpen coach, andRamón Vázquez, who as a coach had focused on statistical analysis and advanced scouting data, was named quality control coach and interpreter.
• On November 25, the team claimed pitcherJoel Payamps off of waivers from theArizona Diamondbacks.^[30] In a corresponding move, pitcherRobert Stock was designated for assignment;^[30] Stock was later claimed off of waivers by theChicago Cubs.^[31]

• On December 1, the team andEduardo Rodríguez reached a one-year deal for the 2021 season, reportedly worth $8.3 million.^[32]
• On December 2, the team reached one-year deals with several players:Matt Barnes,Ryan Brasier,Austin Brice, andKevin Plawecki.^[33]
• On December 3, the team traded minor-league pitcher Yoan Aybar to theColorado Rockies for minor-league infielder Christian Koss;^[34] Aybar had not yet reachedDouble-A, but was on the Red Sox' 40-man roster.
• On December 7,Yairo Muñoz was outrighted off of the 40-man roster and assigned to Triple-A.^[35]
• On December 9, the team announced its 2021Minor League Baseball affiliates; theLowell Spinners, aClass A Short Season affiliate of the Red Sox since 1996, were dropped, as part of an MLB plan to reduce the total number of affiliated minor league teams.^[36]
• On December 10, the team selected pitcherGarrett Whitlock from theNew York Yankees in theRule 5 draft.^[37]
• On December 14, the team signed free agent outfielderHunter Renfroe to a one-year contract.^[38]
• On December 23, catcherDeivy Grullón was claimed off of waivers by theCincinnati Reds.^[39]
• On December 23, the team signed free agentMatt Andriese to a one-year contract.^[40]

• On January 4, the team hiredBianca Smith to serve as a minor-league coach at the team'sFenway South complex, making Smith the first African American woman to serve as a coach in a professional baseball organization.^[41]
• On January 4, the team signed pitcherDaniel Gossett to a minor-league contract.^[42]
• On January 18, the team traded minor-league infielderC. J. Chatham to thePhiladelphia Phillies in exchange for aplayer to be named later.^[43]
• On January 25, the team acquired pitcherAdam Ottavino and minor-league pitcherFrank German from theNew York Yankees for cash considerations or a player to be named later.^[43]

• On February 1,Dustin Pedroia announced his retirement from MLB after a 14-year career, spent entirely with the Red Sox. Knee issues had limited Pedroia to a combined nine games over the 2018 and 2019 seasons, and he missed the entire 2020 season.^[44]
• On February 2, the team signed utility playerEnrique "Kiké" Hernández to a two-year, $14 million contract.^[45]
• On February 3, the team signed pitcherGarrett Richards to a one-year, $10 million contract and, in a corresponding roster move, designated pitcherJoel Payamps for assignment.^[46] Payamps was later claimed off of waivers by theToronto Blue Jays.^[47]
• On February 10, the team tradedAndrew Benintendi and cash considerations to theKansas City Royals as part of a three-team trade in which Boston acquired outfielderFranchy Cordero from the Royals, minor-league pitcherJosh Winckowski from theNew York Mets, and three players to be named later.^[48]
  • On June 4, the players to be named later were identified as three prospects in the low minor leagues: outfielder Freddy Valdez from the Mets, and pitchers Grant Gambrell and Luis De La Rosa from the Royals.^[49]
• On February 12, the team re-signed pitcherMartín Pérez to a one-year, $4.5 million contract; in a corresponding move, pitcherChris Mazza was designated for assignment.^[50]
• On February 16, the team signed free agent pitcherHirokazu Sawamura, who previously played inNippon Professional Baseball, to a two-year, $3 million contract; in a corresponding move, pitcherJeffrey Springs was designated for assignment.^[51]
• On February 17, the team traded pitchersChris Mazza andJeffrey Springs to theTampa Bay Rays in exchange for minor-league catcherRonaldo Hernández and minor-league infielder Nick Sogard.^[52]
• On February 18, the team claimed pitcherJohn Schreiber off waivers from theDetroit Tigers. To make room on the 40-man roster, pitcherChris Sale was placed on the 60-day injured list.^[53]
• On February 22, the team re-claimed Joel Payamps off waivers from Toronto.^[54]
• On February 24, the team signed free agentutility playerMarwin González to a one-year contract; in a corresponding move, pitcherMarcus Walden was designated for assignment.^[55]

• On March 6,Joel Payamps was again claimed off of waivers by the Toronto Blue Jays.^[56]
• On March 7, the team signed free agent infielderDanny Santana to a minor-league contract.^[57]

April 1–April 4, vs.Baltimore Orioles

Rain caused Boston's first game to be postponed from April 1 to April 2.Nathan Eovaldi started the opener, as he had done the prior season, lasting5+1⁄3 innings while allowing one run on four hits and striking out four batters. The Red Sox were limited to two hits and two walks, taking a 3–0 loss. Baltimore also took the second game of the series, 4–2. Red Sox starterTanner Houck held the Orioles to two runs on six hits in five innings, while striking out eight. The Orioles completed the sweep with an 11–3 win in the third game of the series.Garrett Richards took the loss in his first start for Boston, allowing six runs on seven hits in two innings.J. D. Martinez hit the Red Sox' first home run of the season. The most recent time the Red Sox had started a season 0–3 at Fenway Park was1948,^[74] opening that season with losses to thePhiladelphia Athletics.^[75]

Red Sox lost the series 0–3 (5–18 runs)

April 5–April 7, vs.Tampa Bay Rays

The Red Sox' first win of the season came in the series opener against Tampa Bay, 11–2. StarterNick Pivetta pitched five scoreless innings and got the win.J. D. Martinez hit his second home run of the season, whileXander Bogaerts had four hits and an RBI. The Red Sox tied the second game of the series at 3–3 in the bottom of the ninth inning via aChristian Vázquez home run, sending the game intoextra innings. After a scoreless 10th inning, the teams traded runs in the 11th inning, making the score 4–4. After Tampa Bay took a 5–4 lead in the top of the 12th inning, Martinez hit a two-out double in the bottom of the 12th with runners at second and third, driving in both runs and giving Boston a 6–5 victory. Red Sox relieverPhillips Valdéz got the win. Boston completed the sweep with a 9–2 win in the third game of the series, as starterNathan Eovaldi went seven innings while striking out seven and holding the Rays to three hits and one run. Vázquez hit his second home run of the season and Bogaerts went 3-for-3.

Red Sox won the series 3–0 (26–9 runs)

April 8–April 11, atBaltimore Orioles

The Red Sox' first road game of the year was a 7–3 win at Baltimore in the Orioles' home opener. StarterEduardo Rodríguez, who had missed the 2020 season due tomyocarditis, got the win.Rafael Devers andKiké Hernández both homered. The second game of the series went into extra innings after the Red Sox tied the game, 4–4, in the top of the ninth. After Boston scored two runs in the top of the 10th,Matt Andriese held the Orioles scoreless in the bottom of the inning, securing his firstsave of the season and the Red Sox' fifth consecutive win. Devers again homered. Boston completed the sweep with a 14–9 win in the final game of the series, after building a 9–1 lead through five innings. StarterNick Pivetta earned his second win of the season, while the offense had six home runs—three byJ. D. Martinez, two by Devers, and one byAlex Verdugo.

Red Sox won the series 3–0 (27–16 runs)

April 12–April 15, atMinnesota Twins

The opener of a four-game series inMinneapolis was postponed shortly before its scheduled start time, for "the safety of all of those involved" following thekilling of Daunte Wright the day before in nearbyBrooklyn Center, Minnesota.^[76] The postponed game was rescheduled as part of a single-admissiondoubleheader on April 14, with both games seven-inning contests per 2021 MLB rules for doubleheaders.^[77] The Red Sox won the first game played in the series, 4–2, with relieverAdam Ottavino collecting the win andMatt Barnes earning his firstsave of the season.Hunter Renfroe andRafael Devers both homered, as Boston extended theirwinning streak to seven games. For the doubleheader, Boston activated pitcherEduard Bazardo as their extra player.^[78] The first game of the doubleheader was a 3–2 Red Sox victory, with starterNathan Eovaldi getting the win; Barnes recorded the save. The Red Sox extended their winning streak to nine games via a 7–1 win in the second game of the doubleheader.Eduardo Rodríguez started and got the win; Bazardo pitched a scoreless inning of relief in his MLB debut.Alex Verdugo was 3-for-4 at the plate with a home run and three RBIs. The winning streak ended with a 4–3 loss to the Twins in the final game of the series, with the deciding run coming in the bottom of the ninth inning off of reliever Ottavino, who took the loss. The Red Sox were limited to four hits; Verdugo drove in all three Boston runs.

Red Sox won the series 3–1 (17–9 runs)

April 16–April 19, vs.Chicago White Sox

The opening game hosting the White Sox was postponed due to inclement weather, and was rescheduled to be played as part of a separate-admission doubleheader two days later.^[79] The Red Sox won the first game played, 7–4, breaking a 3–3 tie with a four-run eighth inning. RelieverAdam Ottavino got the win,Marwin González homered, and bothKiké Hernández andXander Bogaerts went 4-for-5 at the plate. Chicago won the first game of the doubleheader, 3–2 in seven innings, as starterTanner Houck took the loss. Hernández homered. The second game of the doubleheader was also won by the White Sox, 5–1 in seven innings, with the loss going to starterMartín Pérez. Boston won the final game of the series, 11–4, behind an early offensive outburst. Hernández,J. D. Martinez, andAlex Verdugo all hit home runs while White Sox starterLucas Giolito was chased from the game in the second inning without recording an out. All Red Sox starters reached base, withBobby Dalbec the only one that did not record a hit.

Red Sox split the series 2–2 (21–16 runs)

April 20–April 21, vs.Toronto Blue Jays

The Red Sox won the first game, 4–2, over the Blue Jays behind a home run fromXander Bogaerts and strong starting pitching fromEduardo Rodríguez, who earned the win.Matt Barnes earned a three-outsave. Toronto won the second and final game of the series, 6–3, as Boston starterGarrett Richards took the loss. Bogaerts again homered.

Red Sox split the series 1–1 (7–8 runs)

April 22–April 25, vs.Seattle Mariners

In the first game of a four-game series, Red Sox starterNick Pivetta allowed only a single hit in six innings of work, although the one hit—by Seattle DHTy France—drove in two baserunners who had walked. The game was tied 2–2 after six innings, and 3–3 after nine innings. In the 10th inning, the Mariners scored four runs (three earned) off of two hits and two walks allowed by relieverDarwinzon Hernández, who took the loss after Boston was unable to score in the bottom of the inning.Rafael Devers homered. In game two, the Red Sox bounced back for a 6–5 win behind a three-hit effort fromAlex Verdugo.J. D. Martinez andXander Bogaerts both contributed home runs. Seattle mounted a rally in the ninth inning capped by aKyle Seager three-run homer, butMatt Barnes was able to hold the lead. RelieverHirokazu Sawamura got his first MLB win. Seattle took the third game of the series, 8–2, handing Boston starterNathan Eovaldi the loss after scoring five runs (four earned) on seven hits in the first five innings. The Red Sox won the final game of the series, 5–3, with four of the runs coming in the first inning off of Mariners starterNick Margevicius, who lasted only1⁄3 of an inning.Eduardo Rodríguez and Matt Barnes earned their fourth win and fourthsave of the season, respectively.

Red Sox split the series 2–2 (16–23 runs)

April 27–April 28, atNew York Mets

Boston took the first game of a two-game series, 2–1, behind the starting pitching ofGarrett Richards. Richards posted 10 strikeouts while walking none in a strong seven-inning effort. The Red Sox scored onBobby Dalbec's first home run of the season and aRafael Devers RBI single. Boston won the second game, 1–0, withChristian Vázquez driving in the only run, in the second inning. Red Sox starterNick Pivetta allowed only one hit in five innings of work, earning the win.Matt Barnes notched his sixthsave of the season.

Red Sox won the series 2–0 (3–1 runs)

April 29–April 30, atTexas Rangers

Texas won the opener of a four-game series, 4–1. Boston was held to three total hits, with their only run driven in byRafael Devers; starterMartín Pérez took the loss. Boston won the second game of the series, 6–1, led by two home runs byJ. D. Martinez and one each byXander Bogaerts and Devers. StarterNathan Eovaldi held the Rangers to one run on four hits in six innings to earn the win. The Red Sox ended April with a record of 17–10, good for first place in theAmerican League East,3+1⁄2games ahead of the second-placeToronto Blue Jays.

The Red Sox entered May atop theAmerican League East with a record of 17–10, having just split the first two games of a four-game series against the Rangers.

May 1–May 2, atTexas Rangers (cont'd)

Texas won the third game of the series, 8–6, outscoring Boston by a 4–1 margin after the fifth inning. StarterEduardo Rodríguez had ano decision with relieverMatt Andriese taking the loss after allowing three runs on three hits in the sixth inning.Hunter Renfroe homered. The Rangers also won the final game of the series, 5–3, scoring three runs (two earned) in the bottom of the eighth inning off of Red Sox relieverAdam Ottavino, who took the loss.Xander Bogaerts was 3-for-4 at the plate including a home run.

Red Sox lost the series 1–3 (16–18 runs)

May 4–May 6, vs.Detroit Tigers

In the opening game of a three-game series, Boston built an 8–2 lead after three innings, and went on to win, 11–7, in a game with 24 total hits and fourerrors. StarterNick Pivetta got the win, andcloserMatt Barnes earned thesave.Alex Verdugo,Xander Bogaerts,Hunter Renfroe, andKiké Hernández each homered. Boston lost the second game of the series inextra innings, 6–5. Trailing by a 3–1 score, the Red Sox tied the game, 3–3, in the seventh inning. With that same score in the top of the 10th inning, the Tigers scored three runs (two earned) off of relieverGarrett Whitlock, who took the loss. Boston's rally in the bottom of the 10th inning came up a run short.J. D. Martinez hit his 10th home run of the season. The final game of the series, which featured 30 total hits and six errors, was won by Boston, 12–9. After taking an early 4–1 lead, the Red Sox were at a 9–8 deficit entering the bottom of the eighth inning, before pushing across their final four runs. RelieverMatt Andriese got the win, andAdam Ottavino notched his first save for Boston.

Red Sox won the series 2–1 (28–22 runs)

May 7–May 10, atBaltimore Orioles

After rain delayed the start of the first game of the series by 98 minutes, Boston won, 6–2, with starterEduardo Rodríguez improving to 5–0 for the season.Bobby Dalbec homered. The Red Sox won the second game of the series, 11–6, with starterGarrett Richards getting the win.Michael Chavis (called up afterKiké Hernández went on theinjured list) andXander Bogaerts each homered. StarterNick Pivetta went to 5–0 on the season via Boston's 4–3 win in the third game of the series.Matt Barnes earned the save;Rafael Devers andHunter Renfroe homered. Baltimore avoided the sweep by winning the final game, 4–1. Devers drove in the only Boston run, via asacrifice fly. RelieverMatt Andriese took the loss, allowing three runs on four hits in two innings.

Red Sox won the series 3–1 (22–15 runs)

May 11–May 13, vs.Oakland Athletics

Oakland won the opening game of a three-game series, 3–2. Boston starterNathan Eovaldi held the A's to one run on two hits in six innings, with the loss going to relieverDarwinzon Hernández who allowed two runs on two hits and a walk in only1⁄3 of an inning.Rafael Devers hit his ninth home run of the season. The second game of the series was also an Oakland win, 4–1. Boston's only run came on a bases-loaded walk in the first inning; the team was held to five hits and left a total of eight men on base. StarterEduardo Rodríguez took the loss. The Red Sox avoided being swept with an 8–1 win in the final game of the series. StarterGarrett Richards earned the win, with relieverGarrett Whitlock earning a three-inningsave.Xander Bogaerts andBobby Dalbec homered.

Red Sox lost the series 1–2 (11–8 runs)

May 14–May 16, vs.Los Angeles Angels

The Red Sox won the series opener against the Angels, 4–3. StarterNick Pivetta held Los Angeles to two runs on four hits in six innings, but received ano decision as the win went to relieverMatt Andriese.CloserMatt Barnes earned his ninthsave of the season.Hunter Renfroe andBobby Dalbec homered. In the second game of the series, Boston built a 4–0 lead through four innings, en route to a 9–0 win. StarterMartín Pérez earned his first win of the season.Alex Verdugo,Xander Bogaerts, andRafael Devers each homered. The Angels won the final game of the series, 6–5, taking a late lead with two runs in the top of the ninth inning off of Barnes, who took the loss. Boston backup catcherKevin Plawecki hit his first home run of the season.

Red Sox won the series 2–1 (18–9 runs)

May 18–May 20, atToronto Blue Jays (in Florida)

Due to travel restrictions related to the COVID-19 pandemic, the Blue Jays began the 2021 season playing home games at their spring training facility—TD Ballpark inDunedin, Florida. The Blue Jays won the opening game of the series, 8–0, scoring five runs in five innings off of Boston starterEduardo Rodríguez, who took the loss. The second game was won by the Red Sox, 7–3. StarterGarrett Richards held the Blue Jays to two runs on seven hits in6+2⁄3 innings and earned the win.Alex Verdugo,J. D. Martinez,Kiké Hernández, andChristian Vázquez each homered. The Red Sox won the final game of the series, 8–7, with three runs in the top of the ninth inning to turn a two-run deficit into a one-run lead. Martinez andBobby Dalbec homered, whileMatt Barnes recorded his 10th save of the season.

Red Sox won the series 2–1 (15–18 runs)

May 21–May 23, atPhiladelphia Phillies

The Red Sox won the first game of a three-game road series in Philadelphia, 11–3, with starterMartín Pérez getting the win. In his debut game with Boston,utility playerDanny Santana homered, whileRafael Devers hit his 12th of the season. The second game was also won by Boston, 4–3, with starterNathan Eovaldi earning his fifth win of the season andcloserMatt Barnes notching his 11thsave. Santana again homered, as didXander Bogaerts. The Phillies won the final game of the series, 6–2, giving Red Sox starterEduardo Rodríguez his third loss of the season. Devers andFranchy Cordero each homered.

Red Sox won the series 2–1 (17–12 runs)

May 25–May 26, vs.Atlanta Braves

Entering a two-game home series with Atlanta, the Red Sox (29–19) were no longer atop the AL East for the first time since early in the season, one-halfgame behind Tampa Bay (30–19). The Braves won the first game, 3–1, with Boston starterGarrett Richards taking the loss. The Red Sox' only run came in the bottom of the first inning, whenRafael Devers washit by a pitch with the bases loaded. The second game, including a two-hour and 53-minute rain delay, was won by Boston, 9–5. StarterNick Pivetta improved his season record to 6–0. Devers andHunter Renfroe both homered.

Red Sox split the series 1–1 (10–8 runs)

May 28–May 30, vs.Miami Marlins

The Red Sox opened a three-game home series against the Marlins with a 5–2 win, in a game ended by rain in the sixth inning. The winning runs were driven in byAlex Verdugo via a three-run homer in the fifth inning. StarterMartín Pérez earned the win. Boston also won the second game of the series, 3–1, which was delayed by rain for 16 minutes but lasted its scheduled nine innings. Attendance at Fenway Park was 25,089 in the first game played following the State of Massachusetts lifting COVID-19 restrictions on sports events.^[7] StarterNathan Eovaldi improved to 6–2 on the season withcloserMatt Barnes allowing one run before securing his 12th save.Rafael Devers andHunter Renfroe each went 3-for-4 at the plate. The final game of the series was postponed due to rain, with an announced makeup date of June 7.^[80]

Red Sox won the series 2–0 (8–3 runs)

May 31, atHouston Astros

This series marked the first time thatAlex Cora visited Houston since theHouston Astros sign stealing scandal became public, which led to Cora being suspended for the 2020 season, due to his role in the scandal while he was Houston's bench coach in 2017.^[81] In the first game of a four-game series, the Astros jumped out to an early 4–0 lead after three innings, en route to an 11–2 win. StarterEduardo Rodríguez took the loss.Hunter Renfroe was the only Boston player with more than one hit, one of them a home run. The Red Sox ended May with a record of 32–21, twogames behind the Tampa Bay Rays in the American League East.

The Red Sox entered June in second place in theAmerican League East with a record of 32–21, having just lost the first game of a four-game series against the Astros.

June 1–June 3, atHouston Astros (cont'd)

Houston won the second game of the series, 5–1, handing Boston starterGarrett Richards his fourth loss of the season.Alex Verdugo had two of the Red Sox' five hits. Houston also won the third game of the series, 2–1, as Boston starterNick Pivetta suffered his first loss of the season.Hunter Renfroe drove in the only Red Sox run. Boston avoided being swept with a 5–1 win in the final game of the series; starterMartín Pérez earned the win.Christian Arroyo hit a three-run home run.

Red Sox lost the series 1–3 (9–19 runs)

June 4–June 6, atNew York Yankees

In the first series of the season against the Yankees, the Red Sox jumped out to an early lead via aRafael Devers three-run home run in the top of the first inning.Nathan Eovaldi held New York to two runs (one earned) on eight hits in six innings to earn the win;Matt Barnes closed out the 5–2 win with his 13thsave of the season. Boston came back from a 2–0 deficit to win the second game of the series, 7–3.Bobby Dalbec had a two-run home, and Devers also drove in two runs.Garrett Whitlock earned the win in relief, while Barnes was brought in to record the final out after the Yankees put two baserunners on in the ninth. The Red Sox completed the sweep with a 6–5 win in the third game of the series. Down 3–1 after six innings, Boston scored twice in the seventh and once in the eighth and held a 4–3 lead in the bottom of the ninth. However, Barnes was unable to convert the save as the Yankees tied the game and forced extra innings.Xander Bogaerts drove in two runs in the top of the tenth, andPhillips Valdéz held the Yankees to one run in the bottom of the inning to secure his first major league save.Alex Verdugo andMarwin González each homered. This was the first time that the Red Sox swept the Yankees in a three-game series atYankee Stadium since June 7–9, 2011.^[9][82]

Red Sox won the series 3–0 (18–10 runs)

June 7, vs.Miami Marlins

In the makeup of a May 30 rainout, Boston won their fifth game in a row, defeating the Marlins, 5–3. StarterNick Pivetta held the Marlins to two runs on seven hits, but left after4+2⁄3 innings—the win was awarded to relieverHirokazu Sawamura, the fourth of six Boston pitchers in the game.Adam Ottavino recorded the final four outs for thesave.

Red Sox won the series 1–0 (5–3 runs)

June 8–June 10, vs.Houston Astros

In the opener of a three-game series, Houston jumped out to an early 6–0 lead and went on to win, 7–1. StarterMartín Pérez only lasted two innings and took the loss.Hunter Renfroe drove in Boston's only run. The Astros also won the second game of the series, 8–3. StarterNathan Eovaldi took the loss after allowing five runs on 11 hits in5+2⁄3 innings.Xander Bogaerts drove in two of Boston's runs via a fourth-inning homer. The third game of the series featured 24 hits, 20 runs, and the ejection of Houston managerDusty Baker, as the Red Sox avoided being swept via a 12–8 win.J. D. Martinez andChristian Arroyo both homered, andChristian Vázquez went 3-for-4 with three RBIs.Darwinzon Hernández, the third of six Boston pitchers, got the win.

Red Sox lost the series 1–2 (16–23 runs)

June 11–June 14, vs.Toronto Blue Jays

Boston was outhit by Toronto, 16–8, in the opener of a four-game series, but came away with a 6–5 win. The Blue Jays held a lead from the top of the first inning until the bottom of the eighth, when the Red Sox tied the score at 5–5. A Toronto error in the bottom of the ninth put a runner on second base, andAlex Verdugo, who went 3-for-4, then drove in the winning run with a single off of theGreen Monster.Bobby Dalbec andChristian Arroyo each homered; relieverGarrett Whitlock got the win. Toronto jumped out to an early 2–0 lead in the second game of the series and went on to win, 7–2. StarterNick Pivetta took the loss. The third game of the series was an 18–4 win by the Blue Jays, who had eight home runs and 20 hits. The eight home runs set a new single-game record for a visiting team at Fenway Park.^[10] StarterMartín Pérez fell to 4–4 on the season after allowing five runs in1+1⁄3 innings. He was followed byRyan Weber, who allowed 11 runs in5+2⁄3 innings. Position players Arroyo andMarwin González each pitched an inning. Offensively, Dalbec andXander Bogaerts each homered. Boston won the final game of the series, 2–1. After the Red Sox held a 1–0 lead from the third inning, BostoncloserMatt Barnes allowed a game-tying home run toVladimir Guerrero Jr. in the top of the ninth inning. In the bottom of the ninth,Rafael Devers drove in the winning run via a one-out double with two men on base. StarterNathan Eovaldi held the Blue Jays to three hits and no runs in6+2⁄3 innings but received ano decision.

Red Sox split the series 2–2 (14–31 runs)

June 15–June 16, atAtlanta Braves

Boston won the opening game of a two-game series, 10–8, after building an early 5–0 lead.Rafael Devers,Hunter Renfroe,Xander Bogaerts, andAlex Verdugo each homered. StarterEduardo Rodríguez left after four innings, having allowed four runs on six hits; relieverHirokazu Sawamura, the fourth of six Boston pitchers, got the win.Matt Barnes recorded his 15thsave of the season. The second game of the series was also a Red Sox win by the same score, 10–8.Christian Arroyo hit Boston's firstgrand slam of the season, coming the seventh inning and turning a 6–7 deficit into a 10–7 lead. RelieverYacksel Ríos made his Red Sox debut and earned the win; he was the third of seven Boston pitchers in the game. StarterGarrett Richards allowed six runs on seven hits in four innings;Adam Ottavino earned the save.

Red Sox won the series 2–0 (20–16 runs)

June 18–June 20, atKansas City Royals

Kansas City won the first game of a three-game series, 5–3, dropping Boston starterNick Pivetta to 6–3 on the season.Rafael Devers hit his 17th home run of the season.Christian Arroyo became the first Red Sox player to be ejected during the 2021 season, via a ninth-inning strike-zone disagreement with home plate umpireJim Wolf. The Red Sox were 7–1 winners in the second game of the series, with starterMartín Pérez getting the win.Bobby Dalbec was 3-for-3 including a home run;J. D. Martinez also homered. The win put Boston into a tie with Tampa Bay atop the AL East at 43–28; the Rays later lost to the Mariners, giving the Red Sox sole possession of the divisional lead for the first time since May 22.^[83] The third game of the series was won by the Royals, 7–3. StarterNathan Eovaldi allowed seven hits and four runs in four innings and took the loss. CatcherKevin Plawecki and second baseman Arroyo both left the game with injuries.^[84] Devers andKiké Hernández each homered.

Red Sox lost the series 1–2 (13–13 runs)

June 22–June 24, atTampa Bay Rays

Boston won the opener of a three-game series, 9–5 in 11 innings. Boston starterEduardo Rodríguez received ano decision after allowing five runs (three earned) on seven hits in six innings. After the game remained tied, 5–5, for the 6th through 10th innings, Boston scored four unanswered runs in the top of the 11th inning.^[b]Xander Bogaerts was 3-for-5, whileHunter Renfroe had a home run and three RBIs. RelieverDarwinzon Hernández recorded the final four outs and got the win. Tampa Bay won the second game of the series, 8–2, as Boston starterGarrett Richards only lasted1+2⁄3 innings while allowing five runs (four earned) on three hits and four walks. Both teams had six hits, with the Red Sox drawing six walks and the Rays drawing nine. The Rays won the final game of the series, 1–0. Red Sox starterNick Pivetta left the game after6+2⁄3 innings having thrown 100 pitches and not allowing a hit. The Rays collected their first hit with one out in the eighth inning, off of relieverDarwinzon Hernández. With two outs in the ninth inning, Raysdesignated hitterManuel Margot singled, stole second and advanced to third on a throwing error by catcherChristian Vázquez. Margot then scored the only run of the game via awild pitch fromcloserMatt Barnes, who took the loss. The win put Tampa Bay back into first place atop the AL East at 45–31, one-halfgame ahead of Boston at 44–31.

Red Sox lost the series 1–2 (11–14 runs)

June 25–June 27, vs.New York Yankees

The Red Sox honoredDustin Pedroia, who retired in February, in a ceremony prior to the first game of the series.^[86] Boston won the series opener, 5–3. After reaching a 3–3 tie in the middle of the second inning, Boston scored the game's only other runs; one each in the third and eighth innings. StarterMartín Pérez received ano decision after allowing three runs on six hits in3+2⁄3 innings. The win went toGarrett Whitlock, the third of five Boston pitchers;closerMatt Barnes got thesave.Xander Bogaerts andHunter Renfroe each had two RBIs. Boston also won the second game of the series, 4–2. StarterNathan Eovaldi held the Yankees to a single run on seven hits in7+2⁄3 innings and earned the win;Adam Ottavino earned his fifth save of the season in recording the final four outs. Bogaerts and Renfroe each had three hits and an RBI. CatcherConnor Wong collected his first MLB hit. The Red Sox completed the series sweep with a 9–2 win in the third game. StarterEduardo Rodríguez earned the win, holding the Yankees to two runs on five hits in six innings. Boston had four home runs, one each byKiké Hernández,Rafael Devers,J. D. Martinez, andChristian Vázquez. The win put Boston back atop the AL East at 47–31, a one-halfgame ahead of Tampa Bay at 47–32.

Red Sox won the series 3–0 (18–7 runs)

June 28–June 30, vs.Kansas City Royals

The Red Sox opened a four-game series against the Royals with a 6–5 win, recovering from a 5–2 deficit after the first two innings.Hunter Renfroe hit two home runs, whileKiké Hernández andBobby Dalbec each hit one. StarterGarrett Richards received ano decision after allowing five runs on 11 hits in5+2⁄3 innings. The win went to relieverHirokazu Sawamura, the second of four Boston pitchers in the game.CloserMatt Barnes recorded his 17thsave of the season. Boston won the second game of the series, 7–6, extending their winning streak to five games.J. D. Martinez was 2-for-2 with two walks and four RBIs. StarterNick Pivetta left after4+1⁄3 innings; relieverYacksel Ríos recorded the next five outs and earned the win, while Barnes earned another save. The Red Sox extended their winning streak to six games, via a 6–2 win in the third game of the series. Rain delayed the start of the game, and halted play, for a total of two hours and 21 minutes. StarterMartín Pérez earned the win. Martinez and Renfroe each homered. The Red Sox ended June with a record of 50–31, leading the American League East by three games over the Tampa Bay Rays.

The Red Sox entered July atop theAmerican League East with a record of 50–31, having just won the first three games of a four-game series against the Royals.

July 1, vs.Kansas City Royals (cont'd)

The Red Sox' winning streak reached seven games as the team completed a four-game sweep of the Royals with a 15–1 win. StarterNathan Eovaldi held Kansas City scoreless through seven innings, followed by relieverMatt Andriese who pitched the final two innings and allowed only an unearned run. Each Boston starter had at least one hit.Kiké Hernández,J. D. Martinez,Danny Santana, andRafael Devers each homered.

Red Sox won the series 4–0 (34–14 runs)

July 2–July 4, atOakland Athletics

The opener of a three-game road series in Oakland was a 3–2extra innings win for Boston, extending the winning streak to eight games.Kiké Hernández drove in the winning run in the top of the 10th, withAdam Ottavino holding the Athletics scoreless in the bottom of the inning for thesave.CloserMatt Barnes, who blew a save in the bottom of the ninth, was credited with the win. StarterEduardo Rodríguez allowed no runs and only a single hit in six innings, but had to settle for ano decision. The second game of the series also went to extra innings, tied 4–4. After Boston starterGarrett Richards held Oakland to two runs on five hits in five innings, the Athletics tied the game in the eighth inning via two runs off of relieverYacksel Ríos.J. D. Martinez, playing left field, threw out Athletics catcherSean Murphy at the plate in the bottom of the 10th inning, preserving the tie. After a scoreless 11th inning, the Red Sox scored twice in the top of the 12th to take a 6–4 lead. However, Oakland scored three runs off ofMatt Andriese in the bottom of the inning for a 7–6 win. Hernández hit his 10th home run of the season. The final game of the series was a 1–0 Boston win, with the only run of the game coming on a double–single–ground-out sequence in the sixth inning.Alex Verdugo scored the run, and was the only player in the game with more than one hit. StarterNick Pivetta allowed just two hits in seven innings for the win, while Barnes earned his 19th save of the season.

Red Sox won the series 2–1 (10–9 runs)

July 5–July 7, atLos Angeles Angels

The first game of a three-game series with the Angels was won by the Red Sox, 5–4. StarterMartín Pérez got the win, having held Los Angeles to one run on eight hits in5+1⁄3 innings.Adam Ottavino notched his seventh save of the season.Rafael Devers had three hits, include a home run;Christian Arroyo also homered. The Angels won the second game of the series, 5–3, with all their runs scored off of starterNathan Eovaldi, who lasted5+2⁄3 innings and took the loss.Hunter Renfroe homered. The final game of the series was a 5–4 Angels win, dropping starterEduardo Rodríguez to a 6–5 record for the season.Xander Bogaerts went 3-for-4 at the plate.

Red Sox lost the series 1–2 (12–14 runs)

July 9–July 11, vs.Philadelphia Phillies

Boston won the opener of a three-game home series against the Phillies, 11–5. StarterGarrett Richards got the win, improving to 5–5 on the season. Six different Red Sox batters had two hits apiece, whileJ. D. Martinez,Kiké Hernández, andRafael Devers each homered. The Phillies won the second game of the series, 11–2. Holding a 3–2 lead after seven innings, Philadelphia scored eight runs in the top of the eighth inning to put the game out of reach. StarterMartín Pérez allowed three runs on six hits, exiting after3+2⁄3 innings and taking the loss.Xander Bogaerts hit his 14th home run of the season. The final game of the series was another Phillies win, 5–4. StarterNick Pivetta took the loss against his former team, allowing five runs on four hits in four innings. Bogaerts homered again. The Red Sox reached the All-Star break atop theAmerican League East with a record of 55–36,1+1⁄2games ahead of Tampa Bay.

Red Sox lost the series 1–2 (17–21 runs)

The Red Sox had five players selected to the All-Star Game; all five played as theAmerican League defeated theNational League, 5–2.^[87]Xander Bogaerts andRafael Devers started the game at shortstop and third base, respectively. Bogaerts went 2-for-3 at the plate with an RBI, while Devers went 1-for-2. They were replaced by reserve players in the bottom of the fifth inning.Nathan Eovaldi pitched the fourth inning, allowing no runs on one hit.J. D. Martinez entered the game asdesignated hitter in the top of the fifth inning and went 0-for-2.Matt Barnes pitched the eighth inning, allowing no runs on two hits and a walk.

July 15–July 18, atNew York Yankees

The opener of a four-game series atYankee Stadium was postponed due to three positiveCOVID-19 test results within the Yankees' pitching staff.^[88] The next day, Boston won the first game played in the series, 4–0. StarterEduardo Rodríguez allowed only two hits in5+2⁄3 innings and earned the win.Tanner Houck pitched the final three innings, earning asave.Christian Arroyo andJ. D. Martinez each homered. The Yankees won the second game of the series, 3–1, in a six-inning rain-shortened contest. StarterNathan Eovaldi held the Yankees to one run on two hits in five innings, leaving with ano decision. RelieverHirokazu Sawamura allowed two home runs in the bottom of the sixth, and took the loss. The game included the MLB debut ofJarren Duran, the ejections of bench coachWill Venable and backup catcherKevin Plawecki following a check-swing third-strike call that the Red Sox dugout took exception to, and a brief stoppage in play after left fielderAlex Verdugo was struck in the back by a baseball thrown by a fan.^[89] The final game of the series was a 9–1 New York win, as starterMartín Pérez allowed three runs on five hits in four innings, taking the loss.Xander Bogaerts was the only Red Sox batter with two hits, whileHunter Renfroe had the only RBI.

Red Sox lost the series 1–2 (6–12 runs)

July 19–July 21, atToronto Blue Jays (in Buffalo)

Boston won the first game of a three-game series played inBuffalo, New York, 13–4.J. D. Martinez was 4-for-4 with a walk, whileKiké Hernández hit two home runs. Boston also had home runs fromJarren Duran,Hunter Renfroe (agrand slam),Rafael Devers, andDanny Santana. StarterNick Pivetta allowed four runs on 11 hits in6+2⁄3 innings and earned the win. The second game of the series was rained out, with a makeup game scheduled for August 7.^[90] Boston won the final game of the series, 7–4. StarterGarrett Richards earned the win, allowing four runs on four hits in5+2⁄3 innings, andMatt Barnes earned his 20thsave of the season. Hernández, Devers, Martinez, Renfroe, andMichael Chavis each homered.

Red Sox won the series 2–0 (20–8 runs)

July 22–July 25, vs.New York Yankees

The first game of a four-game home series against the Yankees was a 5–4 extra-innings win. StarterTanner Houck left after4+2⁄3 innings due to a 55-minute rain delay, having held New York to oneunearned run on two hits. Trailing 3–1 entering the bottom of the ninth,Kiké Hernández drove in two runs via a two-out double to tie the game. The Yankees scored one run off ofMatt Barnes in the top of the 10th. In the bottom of the inning, Boston scored twice, taking advantage of fourwild pitches by Yankees relieverBrooks Kriske;Hunter Renfroe drove in the winning run via asacrifice fly. The second game of the series was a 6–2 Boston win. Trailing 1–0 entering the bottom of the fifth, the Red Sox scored three runs, then added three more in the bottom of the seventh.Rafael Devers had five RBIs via two home runs. StarterEduardo Rodríguez left in the second inning due tomigraine symptoms.^[91]Yacksel Ríos, the third of five Boston relievers who followed Rodríguez, allowed no runs or hits in two innings of work and got the win. In the second game of the series, Boston took an early 3–0 lead, but the Yankees scored four unanswered runs in the eighth inning to give the Red Sox a 4–3 defeat. StarterNathan Eovaldi lasted7+2⁄3 innings and allowed two runs on seven hits; relieverAdam Ottavino allowed two runs on three hits in1⁄3 of an inning and took the loss.Kevin Plawecki was the only Boston batter with two hits. The final game of the series was a 5–4 Red Sox win. Entering the bottom of the eighth inning, Boston had not recorded a hit and trailed, 4–0. Five consecutive hits and asacrifice fly put the Red Sox ahead by a run. Barnes then closed out the game for his 21stsave of the season. The win went toBrandon Workman, the third of four relievers who followed starterMartín Pérez.

Red Sox won the series 3–1 (19–14 runs)

July 26–July 29, vs.Toronto Blue Jays

The Red Sox won the first game of a four-game home series against Toronto, 5–4. Boston's 3–2 fifth-inning lead became a 4–3 deficit via a two-runBo Bichette homer.Alex Verdugo's own two-run homer in the eighth inning put Boston back in the lead, allowingMatt Barnes to close out the game with his 22ndsave of the year. StarterNick Pivetta had ano decision after allowing four runs on six hits in4+2⁄3 innings; relieverAdam Ottavino got the win.Rafael Devers also homered. The second game of the series was postponed due to rain, resulting in adoubleheader being scheduled for the following day.^[92] The first game of the doubleheader was won by the Blue Jays, 4–1, in seven innings. StarterGarrett Richards allowed four runs on eight hits in four innings and took the loss.J. D. Martinez drove in Boston's only run. The second game of the doubleheader was a Boston win, also by a 4–1 score in seven innings. StarterTanner Houck allowed one run in four innings; the win went to relieverGarrett Whitlock, who pitched two scoreless innings, while Barnes registered another save.Kevin Plawecki had three hits, andJarren Duran had two RBIs. The final game of the series was a 13–1 Blue Jays win, with starterEduardo Rodríguez taking the loss after allowing six runs in3+1⁄3 innings.Bobby Dalbec drove in Boston's only run. Red Sox backup catcher Plawecki pitched a scoreless ninth inning.

Red Sox split the series 2–2 (11–22 runs)

July 30–July 31, atTampa Bay Rays

Tampa Bay won the opener of a three-game series, 7–3, dropping starterMartín Pérez to a 7–7 record for the season. The second game of the series was also won by the Rays, 9–5. StarterNathan Eovaldi allowed six runs (five earned) on six hits in5+1⁄3 innings and took the loss.Xander Bogaerts andBobby Dalbec each homered. The Rays ended July back in the lead of theAmerican League East with a 63–42 record, one-halfgame ahead of the Red Sox at 63–43.^[93]

The Red Sox entered August in second place in theAmerican League East with a record of 63–43, having just lost the first two games of a three-game series against the division-leading Rays (63–42).

August 1, vs.Tampa Bay Rays (cont'd)

The Rays completed a three-game sweep with a 3–2 win. Red Sox startedNick Pivetta took the loss; he allowed three runs on three hits in4+2⁄3 innings.Kiké Hernández had three hits andHunter Renfroe homered. Boston had runners at first and third with two outs in the ninth, but were unable to push across the tying run.

Red Sox lost the series 0–3 (10–19 runs)

August 3–August 5, atDetroit Tigers

Detroit defeated Boston, 4–2, in the opener of a three-game series, extending the Red Sox' losing streak to five games. StarterGarrett Richards allowed three runs on five hits in four innings and took the loss.Hunter Renfroe homered. Boston won the middle game of the series, 4–1, asEduardo Rodríguez improved to 8–6 on the season, allowing no runs on two hits in five innings.J. D. Martinez,Kiké Hernández, andJarren Duran each homered, whileMatt Barnes notched his 24thsave of the season. The Tigers won the final game, 8–1. Red Sox starterMartín Pérez left after1+1⁄3 innings, having allowed three runs on five hits, and took the loss.Alex Verdugo drove in Boston's only run.

Red Sox lost the series 1–2 (7–13 runs)

August 6–August 8, atToronto Blue Jays

Toronto won the first game of a four-game series, 12–4, powered by a nine-run fifth inning. StarterNathan Eovaldi allowed seven of those runs, and took the loss. InfielderJonathan Araúz pitched the bottom of the eighth inning for Boston.Hunter Renfroe homered. Toronto won the second game of the series (also the first game of adoubleheader), 1–0. Each team only had two hits. The game's only score was awalk-off home run hit byMarcus Semien off ofMatt Barnes to start the bottom of the seventh inning. The Red Sox won the second game of the doubleheader, scheduled for seven innings, 2–1 in eight innings. With Toronto holding a 1–0 lead entering the sixth,Alex Verdugo homered to tie the contest. With no further scoring through the seventh, Boston scored one run in the eighth, driven in by Araúz.Adam Ottavino then held the Blue Jays scoreless to earn his eighthsave of the season. The win went to Barnes, who had pitched the seventh inning; starterTanner Houck went3+2⁄3 innings and had ano decision. Toronto won the final game of the series, 9–8, overcoming a 7–2 Boston lead after four innings. Red Sox starterGarrett Richards allowed four runs (three earned) on six hits in five innings, while Barnes took the loss after allowing a three-run homer toGeorge Springer in the eighth inning.J. D. Martinez was 4-for-5 with three RBIs andKevin Plawecki was 3-for-4 also with three RBIs.

Red Sox lost the series 1–3 (14–23 runs)

August 10–August 12, vs.Tampa Bay Rays

Boston had a 4–1 lead in the first game of a three-game home series, but Tampa Bay rallied for an 8–4 win. It was the 10th Red Sox loss in 12 games. StarterEduardo Rodríguez went5+1⁄3 innings while allowing two runs on four hits;Matt Barnes took the loss in relief after allowing four runs on two hits in2⁄3 of an inning.Rafael Devers andHunter Renfroe homered. Boston recovered in the second game of the series with a 20–8 win, the most Red Sox runs scored in a single game since the2015 season.^[94]Bobby Dalbec had 5 RBIs on the night, and Renfroe andXander Bogaerts each added 4 RBIs of their own. Boston's 19 hits included only one home run, by Bogaerts. StarterNathan Eovaldi tossed seven innings of three-hit ball, surrendering one run, and earned his 10th win of the season. The Rays’Josh Fleming was charged with 10 earned runs in3+1⁄3 innings pitched. Tampa Bay won the final game of the series, 8–1. Red Sox starterTanner Houck allowed four runs (three earned) on six hits in five innings, and took the loss. Devers drove in Boston's only run.

Red Sox lost the series 1–2 (25–24 runs)

August 13–August 15, vs.Baltimore Orioles

Boston won the opener of a three-game home series against the Orioles, 8–1. StarterNick Pivetta went six innings and got the win, improving to 9–5 on the season, whileGarrett Richards pitched the final three innings to earn asave.Bobby Dalbec was 3-for-4 with a home run and three RBIs.Xander Bogaerts andHunter Renfroe also homered.Kyle Schwarber made his Red Sox debut, going 0-for-2 with two walks and two runs scored as theDH. The second game of the series marked the return ofChris Sale to the Red Sox, following hisTommy John surgery and subsequent rehabilitation. Sale went five innings while allowing two runs on six hits and earned the win as Boston defeated Baltimore, 16–2.Alex Verdugo went 4-for-5 with an RBI and three runs scored. The Red Sox had two home runs from Dalbec, and one each from Renfroe,Rafael Devers, andJ. D. Martinez. Boston completed the sweep with a 6–2 win in the third game of the series. StarterEduardo Rodríguez earned his ninth win of the season, holding the Orioles to one unearned run on three hits in six innings. Martinez again homered, and had three RBIs.

Red Sox won the series 3–0 (30–5 runs)

August 17–August 18, atNew York Yankees

Boston opened a three-game road series in New York with a loss in the first game of adoubleheader, 5–3. StarterTanner Houck had ano decision after holding the Yankees to two runs on five hits in four innings. RelieverGarrett Whitlock allowed two runs in1⁄3 of an inning and took the loss.Christian Vázquez had a solo home run, whileXander Bogaerts had the other two RBIs for Boston. The second game of the doubleheader was also won by the Yankees, 2–0. Both runs were scored off of Red Sox starterNathan Eovaldi in his five innings of work, dropping him to 10–8 on the season. Boston was limited to five hits, all singles, and four walks. The loss left Boston (69–53) in third place in theAL East standings, a percentage point behind the Yankees (68–52).^[95] The Yankees completed their sweep with a 5–2 win in the third game of the series. Boston's runs came on solo homers by Bogaerts (first inning) andHunter Renfroe (ninth inning). StarterNick Pivetta took the loss after allowing four runs on four hits in1+2⁄3 innings.

Red Sox lost the series 0–3 (5–12 runs)

August 20–August 23, vs.Texas Rangers

The Red Sox opened a three-game home series with a 6–0 win over the Rangers. StarterChris Sale went five innings, allowing five hits, and got the win.Xander Bogaerts hit his 20th home run of the season. Texas won the second game of the series, 10–1, withKiké Hernández driving in Boston's only run. StarterEduardo Rodríguez took the loss after allowing five runs on eight hits in3+2⁄3 innings. The Red Sox were limited to five hits, while also committing five errors. The final game of the series was postponed a day, due to the effects ofHurricane Henri.^[96] The Red Sox won that game, 8–4 in 11 innings. StarterNathan Eovaldi held Texas to one run on four hits in seven innings and left with a 3–1 lead, but ultimately received ano decision. With Boston still holding a 3–1 lead entering the top of the ninth, the Rangers scored twice off ofcloserMatt Barnes to tie the game. The game went to extra innings, and both teams scored a single run in the 10th inning. In the 11th inning, the Rangers did not score, and the Red Sox won the game on awalk-offgrand slam byTravis Shaw. RelieverGarrett Whitlock got the win after pitching the final2+2⁄3 innings for Boston. In addition to Shaw,Alex Verdugo andHunter Renfroe also homered.

Red Sox won the series 2–1 (15–14 runs)

August 24–August 26, vs.Minnesota Twins

The opener of a three-game home series against Minnesota was an 11–9 Boston win. StarterTanner Houck had ano decision after allowing three runs on eight hits in4+2⁄3 innings. RelieverJosh Taylor, who recorded one out on one pitch to close out the fifth inning, got the win.CloserMatt Barnes allowed a home run and two walks while recording no outs in the ninth inning. He was relieved byHansel Robles, who earned thesave, his 11th of the season and first with the Red Sox. Boston hitters had four home runs: two byHunter Renfroe and one each byTravis Shaw andKiké Hernández. The Twins won the second game of the series, 9–6 in 10 innings. Red Sox starterNick Pivetta allowed four runs on six hits in four innings. Boston did not score until the seventh inning, and entered the bottom of the ninth trailing, 4–2. A two-run home run byKyle Schwarber tied the game, which then went toextra innings. Robles came in to pitch the 10th for Boston, and allowed five runs via two homers. Robles took the loss after the Red Sox only scored twice in their half of the inning, one run coming on a Hernández homer. The final game of the series was a 12–2 victory by the Red Sox, withChris Sale getting the win after holding the Twins to two runs on two hits in5+1⁄3 innings.Rafael Devers hit his 30th home run of the season, whileBobby Dalbec homered twice and drove in seven runs.

Red Sox won the series 2–1 (29–20 runs)

August 27–August 29, atCleveland Indians

The Red Sox defeated the Indians, 4–3, in the first game of a three-game series. Prior to the game,Kiké Hernández andChristian Arroyo were placed on the COVID-relatedinjured list.^[97] StarterEduardo Rodríguez notched his 10th win of the season after holding Cleveland to three runs on eight hits in seven innings.Adam Ottavino got thesave.Jonathan Araúz, just called up from Triple-A, had a three-run homer, one of only three Boston hits. Boston also won the second game of the series, 5–3 in 10 innings. StarterNathan Eovaldi went5+1⁄3 innings while allowing two runs on six hits.Kyle Schwarber had a first-inning home run, helping to stake the Red Sox to an early 2–0 lead. After Cleveland tied the game, 2–2, in the second inning, there was no more scoring untilextra innings.J. D. Martinez put the Red Sox ahead on a three-run homer. The Indians got one run back off ofMartín Pérez, who was relieved by Ottavino who earned his 10th save of the season. The win went toGarrett Whitlock, who pitched a scoreless inning as the sixth of eight total Boston pitchers. The Twins won the final game of the series, 7–5, despite Boston building a 4–0 lead after five innings. StarterTanner Houck went5+1⁄3 innings and allowed three runs on one hit and four walks.Austin Davis, the fourth of five Boston pitchers, allowed three runs on three hits and took the loss.Rafael Devers had two home runs andBobby Dalbec had one.

Red Sox won the series 2–1 (14–13 runs)

August 30–August 31, atTampa Bay Rays

The Red Sox lost the opener of a four-game series in Tampa Bay, 6–1. RelieversMartín Pérez andMatt Barnes were not available due to being placed on the COVID-relatedinjured list.^[98] StarterNick Pivetta allowed four runs on six hits in five innings and took the loss. A homer byBobby Dalbec accounted for Boston's only run. Prior to the second game of the series, relieversJosh Taylor andHirokazu Sawamura were also placed on the COVID-related list, and during the game, shortstopXander Bogaerts was removed due to a positive test.^[99] Tampa Bay won the game, 8–5, with Boston starterBrad Peacock taking the loss in his Red Sox debut after allowing five runs on two hits in2+1⁄3 innings.Kyle Schwarber homered. Boston ended the month in third place in theAmerican League East, still in position for the postseason as awild card, with a record of 75–59.

The Red Sox entered September with eight players unavailable due to positiveCOVID-19 testing orcontact tracing: pitchersMatt Barnes,Martín Pérez,Hirokazu Sawamura, andJosh Taylor; and position playersChristian Arroyo,Xander Bogaerts,Kiké Hernández, andYairo Muñoz.^[100][101] Three staff members were also unavailable due to testing or tracing: quality control coachRamón Vázquez, first base coachTom Goodwin, and conditioning coach Kiyoshi Momose.^[102] With a record of 75–59, and having just lost the first two games of a four-game series against Tampa Bay, the Red Sox were positioned as awild card team, in third place in theAL East.

September 1–September 2, atTampa Bay Rays (cont'd)

Boston won the third game of the series, 3–2. StarterChris Sale went six innings, holding the Rays to two runs on six hits. RelieverGarrett Whitlock pitched two scoreless innings and got the win;Adam Ottavino earned thesave, his 11th of the season.Christian Vázquez went 3-for-4 with a home run and two RBIs;Jarren Duran drove in Boston's other run, a go-ahead RBI in the ninth inning to break a 2–2 tie. The final game of the series was another Red Sox win, 4–0. StarterEduardo Rodríguez went six innings and won his 11th game of the year.Garrett Richards pitched the final three innings, earning a save.Bobby Dalbec went 2-for-4 with two RBIs.

Red Sox split the series 2–2 (13–16 runs)

September 3–September 5, vs.Cleveland Indians

Prior to the first game against Cleveland, outfielderJarren Duran became Boston's ninth player on the COVID-related list.^[103] The Red Sox opened the three-game series with an 8–5 win. StarterNathan Eovaldi held Cleveland to three runs on six hits in6+1⁄3 innings; he was relieved byAdam Ottavino, who was credited with the win;Garrett Whitlock earned asave.Kyle Schwarber had three RBIs, one coming on a leadoff home run in the first inning.Hunter Renfroe also drove in three runs, via a seventh-inning home run with two men on base.Kevin Plawecki andJonathan Araúz each hit solo home runs. Boston also won the second game of the series, 4–3, the team's fourth consecutive win. StarterTanner Houck kept the Indians scoreless through five innings, but ended up with ano decision. A three-run home run byRafael Devers in the seventh inning gave the Red Sox a 3–0 lead; with his 33rd home run of the season, Devers reached 100 RBIs for the second time in his career.^[104] In the top of the ninth, Cleveland scored three runs off of Ottavino to tie the game. After Boston loaded the bases with two outs in the bottom of the ninth,Alex Verdugo singled to drive in the winning run. Prior to the final game of the series, pitcherNick Pivetta and utility playerDanny Santana were also added to the COVID-related list, bringing the Red Sox' total to 11 players.^[105] The final game was won by Cleveland, 11–5. After the Indians built a 6–0 lead after three innings, the Red Sox battled back within a run, 6–5, at the end of the sixth, only to have the Indians score five runs in the top of the ninth to put the game out of reach.Kutter Crawford, just called up fromTriple-A and making his MLB debut, took the loss.J. D. Martinez went 3-for-5 with three RBIs and a home run.

Red Sox won the series 2–1 (17–19 runs)

September 6–September 8, vs.Tampa Bay Rays

Despite taking a 7–1 lead after the first two innings of the series' opening game, the Red Sox lost to the Rays, 11–10 in 10 innings. Boston committed fourerrors during the game, making six of Tampa Bay's runs unearned. StarterChris Sale went3+2⁄3 innings and allowed oneearned run (five total runs) on 10 hits.Garrett Whitlock, the sixth of seven Red Sox pitchers, had ablown save and took the loss.Hunter Renfroe was 3-for-5 with two RBIs, andJonathan Araúz homered. Home plate umpireManny Gonzalez was struck by a foul tip in the first inning and had to leave the game.^[106] A rare instance of anintentional balk occurred in the bottom of the 10th inning, when the Rays, holding a two-run lead, had pitcherCollin McHugh intentionally commit abalk, thus advancing the Red Sox runner at second base to third base, in order to avoid the possibility ofsign stealing.^[107] The game took four hours and 54 minutes to complete. The Rays also won the second game of the series, 12–7. StarterEduardo Rodríguez look the loss after allowing six runs in3+2⁄3 innings.Bobby Dalbec had two home runs and four RBIs.Danny Santana also homered. Boston won the final game of the series, 2–1. Scoreless through the first seven innings, the Rays scored once in the top of the eighth, and the Red Sox scored two runs in the bottom of the inning via a Renfroe home run with a runner on base. Renfroe also recorded anoutfield assist on the final out of the game, as Tampa Bay'sJoey Wendle attempted to stretch a double into a triple. Boston starterNathan Eovaldi pitched seven scoreless innings but had ano decision, with the win going toGarrett Richards whileHansel Robles earned thesave. The Red Sox' win put them back in second place of theAL East at 80–62 (.563), one-halfgame ahead of theNew York Yankees at 78–61 (.561), with both teams in position as postseasonwild cards.^[108]

Red Sox lost the series 1–2 (19–24 runs)

September 10–September 12, atChicago White Sox

Prior to the opener of a three-game series in Chicago,Xander Bogaerts was activated from the COVID-related list,^[109] whileChris Sale andJonathan Araúz were added to that list.^[110][111] In the opener, Chicago took a 4–0 lead through four innings, and while the Red Sox then scored three unanswered runs, the game ended 4–3 in the White Sox' favor. StarterTanner Houck allowed all of Chicago's runs and left after3+2⁄3 innings, his record falling to 0–4.Bobby Dalbec hit his 21st home run of the season. Boston won the second game of the series, 9–8 in 10 innings. Prior to the game, utility playerDanny Santana was again added to the COVID-related list.^[112] Boston starterConnor Seabold, making his MLB debut, allowed two runs on three hits in three innings.Garrett Whitlock, the sixth of seven Boston pitchers, earned the win, withJosh Taylor notching his first major-leaguesave.Travis Shaw was 2-for-5 with a home run and four RBIs. On the day of the final game of the series, relieverPhillips Valdéz became the latest Boston player added to the COVID-related list.^[113] Chicago won the game, 2–1. After the White Sox took a 1–0 lead in the bottom of the sixth, the Red Sox tied the game via anAlex Verdugosacrifice fly in the top of the ninth.Leury García then hit awalk-off home run off of Whitlock with two outs in the bottom of the ninth. Boston starterNick Pivetta held Chicago to one run on three hits in5+1⁄3 innings. The loss dropped the Red Sox (81–64; 0.5586) back to third place in theAL East, with Toronto (80–63; 0.5594) moving into second place.

Red Sox lost the series 1–2 (13–14 runs)

September 13–September 15, atSeattle Mariners

Boston lost the opener of a three-game series in Seattle, 5–4. StarterEduardo Rodríguez went six innings, allowing one run on six hits. A three-run homer by Seattle'sMitch Haniger off of Red Sox relieverRyan Brasier put the Mariners ahead, 5–2, in the seventh inning. The runs were unearned, due to a two-outerror by first basemanKyle Schwarber. Back-to-back solo homers byXander Bogaerts andRafael Devers in the eighth inning left the Red Sox a run short.José Iglesias also homered. The loss dropped the Red Sox (81–65; 0.555) to fourth place in theAL East, percentage points behind the Yankees (80–64; 0.556). The Red Sox won the second game of the series, 8–4. StarterNathan Eovaldi allowed two runs on five hits in five innings. Entering the eighth inning with the score tied, 2–2, Boston scored five runs, which proved to be enough to win. Schwarber had a three-RBIpinch hit double as part of the eighth inning rally.Adam Ottavino, the third of six Red Sox pitchers, threw only two pitches and recorded a single out, but got the win.J. D. Martinez,Bobby Dalbec, andAlex Verdugo each homered. Game 3 of the series, an afternoon getaway game, was tied 3–3 after nine innings. All of Seattle's three runs had been allowed by Sox starterTanner Houck, who pitched4+1⁄3 innings. Boston's three runs were made up of aHunter Renfroe solo homer, aKevin Plawecki RBI ground out, and a José Iglesias RBI double. Entering the top of the 10th, the Boston offense immediately went to work, asJack López advanced to third base and then scored on apassed ball to give the Red Sox the lead.J. D. Martinez made it 5–3 on an RBI single before Kyle Schwarber came through in the clutch for the second straight game, delivering a two-run hit to shallow right field. Martinez and Schwarber were then driven in byChristian Vázquez, giving the Red Sox a 9–3 lead.Martín Pérez pitched the bottom of the tenth. Seattle scored one run but was otherwise effectively shut down, and the Red Sox won, 9–4, to win the series against the Mariners.

Red Sox won the series 2–1 (21–13 runs)

September 17–September 19, vs.Baltimore Orioles

The Red Sox began their final home stand of the season with a 7–1 win over the Orioles; it was Baltimore's 100th loss. Boston starterChris Sale, just activated from the COVID-related list, got the win after holding the Orioles to one run on two hits in five innings.Hunter Renfroe had three RBIs,Alex Verdugo had three hits, andBobby Dalbec homered. The win moved Boston back to second place in theAL East, slightly ahead of the Yankees and Blue Jays, with the three teams contesting for twowild card spots in the postseason. Boston won the second game of the series, 9–3, with relieverTanner Houck earning the win. StarterNick Pivetta went3+2⁄3 innings and left with the game tied, 3–3.Xander Bogaerts went 3-for-5 with four RBIs and hit his 22nd home run of the season;Rafael Devers also went 3-for-5. Boston won the final game of the series, 8–6, to complete the sweep. StarterNathan Eovaldi allowed three runs on seven hits in five innings, and had ano decision. RelieverHirokazu Sawamura got the win andGarrett Richards earned asave.J. D. Martinez homered.

Red Sox won the series 3–0 (24–10 runs)

September 21–September 22, vs.New York Mets

The Red Sox opened a two-game series against the Mets with a 6–3 win. StarterEduardo Rodríguez had ano decision after allowing two runs on five hits in4+1⁄3 innings. RelieverRyan Brasier got the win.Kiké Hernández andXander Bogaerts homered. Boston won the second game of the series, 12–5. StarterChris Sale earned the win to reach 5–0 on the season.Kyle Schwarber had two home runs to reach 31 on the season (including ones he hit before joining the Red Sox). The two wins over the Mets extended the Red Sox'winning streak to seven games, five of which came with the team wearing their yellow "City Connect" alternate uniforms.^[114]

Red Sox won the series 2–0 (18–8 runs)

September 24–September 26, vs.New York Yankees

The Red Sox opened their final home series of the season with an 8–3 loss to the Yankees. The loss reduced the Red Sox' lead in the ALwild card race to a single game over the Yankees, the teams holding records of 88–66 (.571) and 87–67 (.565), respectively. StarterNathan Eovaldi took the loss after allowing seven runs on seven hits in2+2⁄3 innings.Rafael Devers hit his 35th home run of the season. The Yankees won the second game of the series, 5–3. Boston starterNick Pivetta held New York to one run on three hits in5+1⁄3 innings. With the Red Sox holding a 3–1 lead entering the eighth inning, Yankeesdesignated hitterGiancarlo Stanton hit agrand slam off of Red Sox relieverDarwinzon Hernández; two of the runs were charged to prior relieverTanner Houck, who took the loss.Bobby Dalbec andKevin Plawecki homered for Boston. Both teams ended the day with records of 88–67 (.568), tied in the AL wild card race. The Yankees completed the sweep with a 6–3 win onSunday Night Baseball, powered by a four-run eighth inning. Boston starterEduardo Rodríguez went five innings, holding the Yankees to two runs on six hits. RelieverGarrett Richards allowed two of the eighth-inning runs and took the loss. The loss put the Yankees atop the AL wild card race at 89–67 (.571) with the Red Sox one game back at 88–68 (.564) and the Blue Jays one more game back at 87–69 (.558). The top two wild card teams qualify for a single-game playoff, hosted by the top wild card team, with the winner advancing to theAmerican League Division Series.

Red Sox lost the series 0–3 (9–19 runs)

September 28–September 30, atBaltimore Orioles

The Red Sox lost the opener of a three-game series in Baltimore, 4–2. StarterChris Sale allowed three runs on four hits in5+1⁄3 innings and took the loss. Boston was limited to three hits, one aKyle Schwarber home run. The day ended with Boston (88–69) still holding the second ALwild card spot, twogames behind the Yankees (90–67), a half-game game ahead of Seattle (88–70) and a full game ahead of Toronto (87–70). Boston won the second game of the series, 6–0, to snap a four-game losing streak. StarterNathan Eovaldi got the win after holding the Orioles to four hits in six innings.J. D. Martinez went 3-for-4 with a home run and three RBIs;Hunter Renfroe also homered. As the Yankees lost to the Blue Jays, Boston (89–69) ended the day one game behind the Yankees (90–68) in the wild card race, with Seattle (89–70) and Toronto (88–70) still in contention. The Orioles won the final game of the series, 6–2. StarterNick Pivetta took the loss after allowing three runs on four hits in4+2⁄3 innings.Kiké Hernández homered for the Red Sox. The loss dropped the Red Sox into a tie with the Mariners for the second AL wild card spot, both teams with 89–70 records.

Red Sox lost the series 1–2 (10–10 runs)

Boston entered October having lost five of their last six games, with three games left to play in the regular season. With the Yankees (91–68) holding the topwild card spot in theAmerican League, the Red Sox (89–70) and Mariners (89–70) were tied for the second wild card spot, followed by the Blue Jays (88–71).

October 1–October 3, atWashington Nationals

To open the final series of the regular season, the Red Sox defeated the Nationals, 4–2. StarterEduardo Rodríguez got the win after holding Washington scoreless through five innings, andHansel Robles earned asave.Hunter Renfroe andBobby Dalbec homered. The Red Sox pulled within a game of the Yankees, who lost to the Rays, for the top wild card spot. The Mariners lost to the Angels, while the Blue Jays stayed in contention by beating the Orioles. Records at the end of October 1: Yankees (91–69), Red Sox (90–70), Mariners (89–71), Blue Jays (89–71)

Boston won the second game against Washington, 5–3. StarterTanner Houck did not allow a baserunner in five innings of work, striking out eight of the 15 batters he faced, but received ano decision.^[115]Austin Davis, the fifth of six Red Sox pitchers, got the win, with Robles again earning a save.Rafael Devers andKike Hernández both homered. With the Yankees losing to the Rays, the Red Sox moved into a tie for the top AL wild card spot. The Blue Jays stayed in contention with a win over the Orioles, as did the Mariners via a late rally to defeat the Angels. Records at the end of October 2: Red Sox (91–70), Yankees (91–70), Mariners (90–71), Blue Jays (90–71)

Boston completed a sweep of the Nationals with a 7–5 come-from-behind win. StarterChris Sale was lifted after2+1⁄3 innings, having allowed two runs on four hits and three walks. Trailing 5–1 after five innings, the Red Sox scored once in the sixth and three times in the seventh to tie the game. A two-run home run by Devers in the ninth inning, his second homer of the game, provided the winning margin.^[116] The win went to Eduardo Rodríguez, who pitched an inning in relief, with the save going toNick Pivetta, who also pitched out of the bullpen as Boston used a total of seven pitchers.^[117] With the Yankees beating the Rays, Boston and New York ended in a tie atop the AL wild card standings, with Boston earning home field advantage via their 10–9 regular-season head-to-head record against New York.^[118] Records at the end of October 3: Red Sox (92–70), Yankees (92–70), Blue Jays (91–71), Mariners (90–72).

Red Sox won the series 3–0 (16–10 runs)

Updated through end of the regular season.
†Minimum 3.1plate appearances per team games played
   AVG qualified batters: Bogaerts, Devers, Hernández, Martinez, Renfroe, Verdugo
‡Minimum 1inning pitched per team games played
   ERA & WHIP qualified pitchers: Eovaldi